Where does “cauterium” come from?

cauterium (Latin) comes from Ancient Greek καυτήρ, from Ancient Greek καίω, from Proto-Hellenic *káyyō.

Ancestry of “cauterium”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	καυτήρ	branding iron
2	Ancient Greek	καίω	I light, kindle, set on fire; I burn, burn up; I...
3	Proto-Hellenic	*káyyō	—

cauterium — Etymology, Origin & Word History | Etymology Explorer